Motion control for extension and retraction arrangements

ABSTRACT

An extension and retraction arrangement with a control system for adjusting a monitor from a retracted configuration to an extended configuration. The control system controls an extension and retraction of a trolley structure and a retained monitor and an opening and closing of a door through which the monitor can be extended. The control system has an operation mode with an UP sequence and a DOWN sequence. Sensors can sense open and closed positions of the door and raised and extended and retracted positions of the trolley and the monitor. The control system can automatically react to monitor positioning issues, losses in power, and obstructions to the travel of the door and the trolley structure.

FIELD OF THE INVENTION

The present invention relates generally to systems for supportingarticles. More particularly, disclosed herein are control and actuationsystems for use in relation to extension and retraction arrangementsenabling an adjustment of a supported article, such as a computer,computer monitor, or other computer component or components, betweenextended and refracted configurations.

BACKGROUND OF THE INVENTION

Computers have become an integral part of our business and personallives. The presence of a computer monitor, a keyboard, or a laptop orother computer component has come to be seen as a necessary evil for theaccomplishment of one's daily tasks. With the computer componentsinherently come wires that further clutter work surfaces. Many computercomponents, particularly computer monitors, have achieved reduced size.However, when not in use, they remain as obstacles to the full usage ofa work surface and contribute to a utilitarian and often displeasingappearance of the work surface and the office in general. Further,continuous exposure leaves the computer components vulnerable not onlyto environmental conditions but also to tampering and theft,particularly as the components become smaller, lighter, and moreportable.

It would be advantageous, therefore, if one could enjoy full usage of acomputer, computer component, or other article when desired while beingable to make the article effectively disappear from a work surface whenits presence is no longer necessary. A number of talented inventors havesought to provide mechanisms for enabling a manipulation of a computeror computer component, such as a monitor, between use and storageconfigurations. To date, however, the proposed solutions of the priorart, such as those disclosed in U.S. Pat. No. 5,526,756 to Watson, U.S.Pat. No. 6,494,150 to Phoenix et al., and U.S. Pat. No. 6,733,094 toChang, have been bulky and inelegant, of limited effectiveness, andrelatively complex in structure and operation. Furthermore, prior artmechanisms and furniture have been ill equipped to accommodate oneanother.

With previous application Ser. Nos. 11/152,994 and 11/152,952 and U.S.Pat. No. 7,517,029, the present inventor has disclosed arrangements forextending and retracting a monitor, computer, or other computercomponent or components that sought to provide improvements in structureand function over the prior art. The disclosed extension and refractionarrangements provide improved systems for efficiently extending atrolley with a support arm to enable use of a monitor or other componentand retracting the trolley, support arm, and component to a storageposition enabling full usage of a work surface. Also disclosed areimproved door constructions for efficiently closing off an aperturethrough which the support arm and component are passed, including whilethe support arm and component are in an extended disposition. Stillfurther, the inventor disclosed systems for manually and electricallycontrolling and propelling the extension and retraction arrangements.

Despite the advantageous improvements represented by these earlierdisclosures, it became clear to the present inventor that there remainedroom for improvements over even those earlier-disclosed systems andmethods. By way of example, it was found that even the most welldesigned extension and retraction system operating under power requireda motion control system and methodology for dealing with initialinstallation, raising and lowering procedures, and procedures in theevent of each possible malfunction, including physical obstructions,power failures, and positional anomalies. It has also been determinedthat it was possible to improve over even the inventor's ownadvantageous door constructions to provide a door arrangement that canbe smoothly and efficiently adjusted between an open position forpermitting passage of a support arm and retained component through anaperture and a closed position substantially entirely closing theaperture not only while the support arm and retained component areretracted but also while the support arm and retained component areextended.

SUMMARY OF THE INVENTION

The present inventor thus set forth with a basic object of providing amotion control system for an extension and retraction system thatprovides procedures for facilitating the initial installation and setupof the extension and retraction system, procedures for the standardraising and lowering a support arm and a retained component, andprocedures for operation in the event of operational malfunctions.

A more particular object of embodiments of the invention is to provide amotion control system for an extension and retraction arrangement thatprevents damage to the system and a retained component in the event ofan obstruction to movement of the support arm or the door arrangement.

Another particular object of particular embodiments of the invention isto provide a motion control system for an extension and retractionarrangement that prevents operation where a retained component is out ofproper orientation for permitting movement of the support arm and theretained component.

A further object of embodiments of the invention is to provide animproved door arrangement that can be smoothly and efficiently adjustedbetween an open position for permitting passage of a support arm andretained component through an aperture and a closed position.

A further object of certain embodiments of the invention is to provide adoor arrangement that can substantially entirely close the aperture notonly while the support arm and retained component are retracted but alsowhile the support arm and retained component are extended.

These and in all likelihood further objects and advantages of thepresent invention will become obvious not only to one who reviews thepresent specification and drawings but also to those who have anopportunity to experience an embodiment of the systems and arrangementsdisclosed herein. However, it will be appreciated that, although theaccomplishment of each of the foregoing objects in a single embodimentof the invention may be possible and indeed preferred, not allembodiments will seek or need to accomplish each and every potentialadvantage and function. Nonetheless, all such embodiments should beconsidered within the scope of the present invention.

One will appreciate that the foregoing discussion broadly outlines themore important goals and features of the invention to enable a betterunderstanding of the detailed description that follows and to instill abetter appreciation of the inventor's contribution to the art. Beforeany particular embodiment or aspect thereof is explained in detail, itmust be made clear that the following details of construction andillustrations of inventive concepts are mere examples of the manypossible manifestations of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

In the accompanying drawing figures:

FIG. 1 is a perspective view of an extension and retraction arrangementpursuant to the invention disclosed herein in an extended configurationand retained in relation to a support structure;

FIG. 2 is a perspective view of the extension and retraction arrangementof FIG. 1 in a partially extended configuration;

FIG. 3 is a perspective view of the extension and retraction arrangementof FIG. 1 in a retracted configuration;

FIG. 4 is a perspective view of an extension and retraction arrangementas disclosed herein apart from a support structure;

FIG. 5 is a perspective view of a further extension and retractionarrangement pursuant to the present invention;

FIG. 6 is an exploded perspective view of an extension and refractionarrangement under the instant invention;

FIG. 7 is a cross sectional view of an extension and retractionarrangement pursuant to the invention disclosed herein;

FIG. 8 is a magnified cross sectional view of the extension andretraction arrangement of FIG. 7;

FIGS. 9A, 9B, and 9C comprise side, front, and top plan views of aportion of a trolley structure under the present invention;

FIG. 10 is a perspective view of a manual actuation arrangement;

FIG. 11 is a perspective view of a motorized actuation arrangement;

FIG. 12 is a perspective view of an alternative manual actuationarrangement;

FIG. 13 is a perspective view of a support arm;

FIG. 14 is a perspective view of a braking arrangement;

FIG. 15 is a cross sectional view of an alternative braking arrangementpursuant to the invention disclosed herein;

FIG. 16 is a perspective view of constant force springs for use in anextension and retraction arrangement;

FIG. 17 is a perspective view of an alternative extension and retractionarrangement;

FIG. 18 is a perspective view of another alternative extension andretraction arrangement;

FIG. 19 is a perspective view of still another extension and retractionarrangement under the present invention;

FIG. 20 is an exploded perspective view of an adjustable arm for usepursuant to the invention;

FIG. 21 is a cross sectioned view in side elevation of an extension andretraction arrangement employing the adjustable arm of FIG. 20;

FIG. 22 is a perspective view of an extension and retraction arrangementemploying an alternative articulated arm;

FIG. 23 is a perspective view of an extension and retraction arrangementpursuant to the present invention retained in relation to a slot wallarrangement;

FIGS. 24A and 24B are perspective views of yet another extension andretraction arrangement under the present invention;

FIG. 25 is an exploded perspective view of an upper portion of anotherextension and retraction arrangement pursuant to the present invention;

FIG. 26 is a partially exploded view of the extension and retractionarrangement of FIG. 25 depicted with upper and lower limit sensors;

FIG. 27 is an exploded perspective view of an upper framework with asliding, articulated door according to the invention disclosed herein;

FIG. 28 is an exploded perspective view of an upper framework with adoor actuation system as taught herein;

FIG. 29 is an exploded perspective view of a door guidance arrangementoperable with the door actuation system of FIG. 28;

FIG. 30 is an exploded perspective view of a motorized trolley and armconfiguration depicted with a monitor angle sensor;

FIG. 31 is an exploded perspective view of a switching arrangement astaught hereunder;

FIG. 32 is an exploded view of a locking arrangement that can beemployed under the present invention; and

FIG. 33 is an assembled perspective view of the locking arrangement ofFIG. 32.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The extension and retraction arrangements disclosed herein are subjectto a wide variety of embodiments. However, to ensure that one skilled inthe art will be able to understand and, in appropriate cases, practicethe present invention, certain preferred embodiments of the broaderinvention revealed herein are described below and shown in theaccompanying drawing figures.

While a flat screen monitor is commonly depicted as the article to besupported and the article is commonly retained relative to a desk orsimilar structure, it is to be understood that other articles andsupport structures are contemplated within the scope of the invention.Furthermore, except where otherwise specified, extension and retractioncan be carried out manually by the user, by a motorized arrangement, orby any combination thereof. Therefore, before any particular embodimentof the invention is explained in detail, it must be made clear that thefollowing details of construction and illustrations of inventiveconcepts are mere examples of the many possible manifestations of theinvention.

Turning more particularly to the drawings, an embodiment of an extensionand retraction arrangement pursuant to the present invention isindicated generally at 10 in FIGS. 1 through 3. In FIG. 1, a supportedarticle, in this example a flat panel computer monitor 12, is shown in afully extended position in relation to a support structure 500, whichcan comprise a desk. The monitor 12 is retained relative to a distalportion of a centrally disposed support arm 54. The support arm 54supports the monitor 12 for extension and retraction through an aperture15 in the support structure 500 by mechanisms described more fullyhereinbelow.

The extension and retraction arrangement 10 has an upper framework 14.An upper flange 26 can be engaged with the upper framework 14 and canoverly the surface of the support structure 500. First and second doors22 and 24 can be pivotally coupled to the upper framework 14 to enable apivoting between the closed configuration shown in FIGS. 1 and 3 and theopen configuration depicted in FIG. 2. An arm aperture 25 can beprovided in either or both of the doors 22 and 24, in this example justthe first door 22, to enable the doors 22 and 24 to reach a fully closedconfiguration even while the monitor 12 and support arm 54 are fullyextended. Advantageously, when the first and second doors 22 and 24 arepivoted to a closed configuration, the aperture 15 in the supportstructure 500 can be effectively sealed, and a generally continuoussurface can be presented, whether below the monitor 12 as in FIG. 1 orabove the monitor 12 as in FIG. 3.

Operation of the first and second doors 22 and 24 can be controlled byany effective means. In certain embodiments, for example, the first andsecond doors 22 and 24 can be spring loaded and latched by a latchingmeans that enables an opening of the first and second doors 22 and 24 bya further depression of the doors 22 and 24 to release the latchingmeans. Alternatively, as will be elaborated upon below, a trigger 88 canenable an automatic opening of the first and second doors 22 and 24 and,additionally or alternatively, a raising of the monitor 12 and thesupport arm 54. Operation of the trigger 88 can be controlled by a lock94 that can be operated by a key 92, a keycard, or any other means.

Use of such an extension and retraction arrangement 10 can begin withthe monitor 12 or other article retained below or within a surface of asupport structure 500. The first and second doors 22 and 24 can beopened, such as by an actuation of the trigger 88. The support arm 54and the retained monitor 12 can then rise through motorization, throughmechanical forces, or, additionally or alternatively, by manualactuation by the user. By means disclosed herein, the monitor 12 andsupport arm 54 can be locked in a fully raised position. Then, the firstand second doors 22 and 24 can, if necessary or desirable, be pivoted toa closed configuration as in FIG. 1. When the monitor 12 or otherarticle is no longer needed, the doors 22 and 24 can be opened and themonitor 12 and support arm 54 can be retracted as in FIG. 2 by anysuitable method including gravity, motorization, mechanical forces,manual actuation, or any combination thereof. Again by means disclosedherein, the monitor 12 and support arm 54 can potentially be locked in aretracted position and the first and second doors 22 and 24 can bemanually or automatically pivoted to a closed configuration as in FIG.3.

An embodiment of an extension and retraction arrangement 10 is depictedapart from the support structure 500 in FIG. 4. There, the extension andretraction arrangement 10 the upper framework 14 can be seen to have aperipheral flange 18 for being retained in relation to a support surface(not shown in FIG. 4) that has an aperture formed therein for receivingthe extension and retraction arrangement 10. A subsurface enclosure 16is fixed to the upper framework 14. The subsurface enclosure 16 definesa protected open inner volume for receiving an article to be retainedwhen the article is in a refracted configuration.

The subsurface enclosure 16 and the upper framework 14 have a sharedopen mouth 20 that can be selectively closed by the pivotally retainedfirst door 22 in combination with the pivotally retained second door 24.One or more apertures 32 can be disposed in a distal portion of thesubsurface enclosure 16 for enabling, among other things, a retrieval ofdebris and a passage of wiring where necessary. Additionally, one ormore wire management apertures 34 can be disposed along a proximalportion of the subsurface enclosure 16 for enabling a passage of wiringand the like. Still further, a removable or pivotable wire managementcover 30 can enable further wiring and other access to the open innervolume of the subsurface enclosure 16. The upper flange 26 can couple tothe upper framework 14 and can overlie an aperture in a support surface.First and second mounting stabilizers 28 can each have a proximalportion fixed to the support surface and, additionally or alternatively,the upper framework 14 and a distal portion fixed to the subsurfaceenclosure 16 for providing stabilizing support thereto.

First and second rails 36 and 38 communicate longitudinally within oralong the subsurface enclosure 16 from adjacent to the distal endthereof to adjacent to the proximal end thereof. The first and secondrails 36 and 38, which are fixed in relation to the subsurface enclosure16 and the upper framework 14, can be formed and fixed in placeseparately. Alternatively, as is shown in FIGS. 4 through 8, the firstand second rails 36 and 38 can be joined with a spine member 40, such asby being unitarily formed therewith as by an extrusion process or thelike or by being fixed thereto.

In either case, a trolley structure 42 can be slidably retained relativeto the first and second rails 36 and 38 for reciprocating movementtherealong between what can be termed an extended disposition as isdepicted in FIG. 4 where the trolley structure 42 is disposed adjacentto the mouth 20 of the subsurface enclosure 16 and the upper framework14 and a retracted disposition where the trolley structure 42 isdisposed adjacent to what can be considered the distal end of thesubsurface enclosure 16. The open inner volume of the subsurfaceenclosure 16 can have a truncated T shape with a head portion of the Tprovided for reception of the article to be supported, such as a monitor12, and the base portion of the T for receiving the first and secondrails 36 and 38 and the spine member 40.

A greater understanding of the trolley structure 42, the first andsecond rails 36 and 38, and the relationship therebetween can be hadwith additional reference to FIGS. 7, 8, and 9A through 9C. The trolleystructure 42 can have a central portion 44 with first and second wingportions 46 and 48 fixed thereto, such as by fasteners 50 or by beingformed integrally therewith. The central portion 44 can have a centrallydisposed alcove 52 with a width W₁ disposed inboard of the first andsecond rails 36 and 38 for receiving a support arm 54 whereby thetrolley structure 42 and the first and second rails 36 and 38 canoperate with a lesser depth D than might otherwise be required.

One exemplary support arm 54 is shown apart in FIG. 13. There, thesupport arm 54 can be seen to have a base portion 136 for being fixed tothe trolley structure 42, such as by mechanical fasteners 56 as in FIG.7, a contoured body portion 142, and a tip portion 138. In this example,the tip portion 138 comprises a sleeve for pivotally retaining a supportplate 144 by use of axle rods 146. The support plate 144 can havethreaded mounting holes 145 therein for enabling a fastening to a flatscreen monitor, such as pursuant to the standardized Video ElectronicsStandards Association Flat Display Mounting Standard for flat panelmonitors.

Each rail 36 and 38 can comprise a side plate 58 with a rigid ventralfin 60 projecting laterally from a ventral side thereof and a rigiddorsal fin 62 projecting laterally from a dorsal side thereof. Aplurality of wheel structures 64 can project inboard from the wingportions 46 and 48 for rolling along one or both of the ventral fin 60and the dorsal fin 62. As FIG. 9C shows, each wheel structure 64 cancomprise an outer wheel 70 rotatably retained relative to an axle 74with a bushing 72 therebetween. While the outer wheels 70 could beformed from a variety of materials, one presently contemplatedembodiment has outer wheels 70 formed from a high strength acetal resin,such as that sold under the trademark DELRIN.

The bushing 72 of each wheel structure 64 can have a head portion forretaining the outer wheel 70 thereon, a body portion for being receivedwithin the outer wheel 70, and a narrowed tip portion for being receivedin an aperture 76 in the wing portion 46 or 48. The tip portion of thebushing 72 can ensure a centering and precise location of the wheelstructure 64 in relation to the aperture 76 and the wing portion 46 or48 in general. Channels 66 and 68 can communicate longitudinally alongthe ventral and dorsal fins 60 and 62 for receiving and engaging thewheels 70 of the wheel structures 64. Each of the outer wheels 70 canhave an arcuate or otherwise contoured profile for engaging acorresponding profile of the channels 66 and 68 thereby to ensure aprecise location and registration of the trolley structure 42 inrelation to the first and second rails 36 and 38.

As previously suggested, the support arm 54 will normally retain anarticle to be supported, such as a monitor or other computer component,to what can be considered the ventral side of the trolley structure 42.As a result, the trolley structure 42 will likely be subjected to atorsion that will tend to press an upper portion of the trolleystructure 42 in a ventral direction while pressing a lower portion ofthe trolley structure 42 in a dorsal direction. To accommodate such atorque most smoothly and effectively, as FIG. 9A shows in relation tothe second wing portion 48, the wing portions 46 and 48 of the trolleystructure 42 can have first and second primary load bearing wheelstructures 64A disposed to the ventral side of the wing portions 46 and48 adjacent to the upper ends thereof and first and second primary loadbearing wheel structures 64A disposed to the dorsal side of the wingportions 46 and 48 adjacent to the lower ends thereof. To maintain thestability of the trolley structure 42 in the event of an oppositetorque, such as might occur where a lifting force is applied thereto, astabilizing wheel structure 64B can be disposed to the dorsal side ofthe wing portions 46 and 48 adjacent to the upper ends thereof and tothe ventral side of the wing portions 46 and 48 adjacent to the lowerends thereof.

Support for the trolley structure 42 and the article retained therebycan be provided by one or more constant force springs 78 and 80. In thisembodiment, each constant force spring 78 and 80 is rotatably retainedrelative to the spine member 40 by an axle 84 with a first end coupledto the spine member 40 and a second end retained relative to alongitudinal fin 82 that projects inboard from the side plate 58 of therail 36 or 38. The axles 84 are separated by a width distance W₂. Theconstant force springs 78 and 80 are shown apart in FIG. 16. Eachconstant force spring 78 and 80 has a distal end fixed to the trolleystructure 42, such as to the alcove portion 52 thereof, by anyappropriate means, such as a mechanical fastener 86, welding, or anyother mechanism.

As shown in FIG. 16, the constant force springs 78 and 80 can comprisetightly coiled wound spring steel with built in curvature. Each turn ofthe springs 78 and 80 can wrap tightly around the next inner turn. Asthe springs 78 and 80 are extended, such as when the trolley 40 andmonitor 12 are lowered, an inherent stress in the springs 78 and 80resists the load at a constant rate thereby ensuring a substantiallyconstant force output. The constant force springs 78 and 80 can beselected to match with the weight of the monitor 12 to be supported. Theconstant force springs 78 and 80 can be calibrated to counterbalance thecombined weight of the trolley 40, support arm 54, and the monitor 12 inan essentially equipoise situation, with a net lifting force thereby totend to raise the monitor 12 automatically, or with a net extensiveforce thereby tending to lower the monitor 12 automatically. Of course,other types and numbers of springs, including compression springs,extension springs, and other types of springs, can be used within thescope of the invention.

Embodiments of the invention can additionally incorporate a means forproviding a braking and cushioning effect at either or both ends oftravel of the trolley 40 and the monitor 12. One such means in depictedin FIGS. 7 and 8 and then alone in FIG. 14 where just a portion of thespine 40 is shown. There, an arcuate braking member 148 has a first endfixed, such as in relation to the spine 40, and a free body portion. Abraking screw 150 is threadedly engaged with the spine 40 to underliethe braking member 148. With this, the braking member 148 willfrictionally engage the trolley structure 42 thereby to slow and controlits travel and, possibly, to prevent an inadvertent lowering of themonitor 12. The degree of braking provided by the braking member 148 canbe adjusted by a rotation of the braking screw 150.

Other braking means are possible pursuant to the invention. For example,an alternative braking arrangement is shown in FIG. 15. There, acompression spring 152 is retained within a spring housing 154, whichcan be formed within or coupled to the spine 40. A projection 156 fromthe trolley structure 42 can project into the spring housing 154 toengage the spring 152 to brake and cushion the travel of the trolleystructure 42 and the retained monitor 12 or other article. A cap member158 can be disposed at a distal end of the spring 152 to ensure apositive engagement with the projection 156, and a stop member 168 canproject from the spring housing 154 into the open inner volume thereofto prevent excessive extension of the spring 152. The initial deflectionof the spring 152 and thus the braking force thereof can be adjusted byan adjustment screw 160 that is rotatably retained relative to an upperportion 162 of the spring housing 154 by a retaining ring 166. Theadjustment screw 160 can be threadedly engaged with an adjustment nut164, which can be separately or integrally formed with the springhousing 154. Under such an arrangement, the spring 152 can provide acushioning and braking effect as the projection 156 engages the spring152.

Referring again to FIG. 4, the embodiment of the extension andretraction arrangement 10 depicted therein can be manually operated. Thefirst and second doors 22 and 24 can be spring-loaded. Their opening canbe triggered by any appropriate method, such as by a pressing thereon orby operation of a switch, such as the trigger 88 or by a remote control(not shown in this drawing). The trolley structure 42 and the articleretained thereby, such as a computer monitor, can automatically extendwhen the doors 22 and 24 are opened. When the article is to be returnedto a storage configuration, a user can simply push the article downwardto cause the trolley structure 42 to slide longitudinally along therails 36 and 38.

The operation and movement of the large and small doors 22 and 24 andthe trolley structure 42 can be controlled by a manual actuatingarrangement 90, which can be understood with combined reference to FIGS.7, 8, and 10. The manual actuating arrangement 90 can be controlled bythe trigger 88. More particularly, a lateral axle 100 can be rotated bya pivoting of the trigger 88. An actuating rod 132 can have a first endcoupled to the lateral axle 100 and a second end coupled to a first legof a pivotally retained L-shaped actuator 133. An engaging member 135with locking tips 137 projecting therefrom can be pivotally coupled to asecond leg of the L-shaped actuator 133. The large and small doors 22and 24 can have spring-loaded disc portions 96 and 98 operablyassociated therewith, such as at each end thereof. With this, asufficient turning of the lateral axle 100 will disengage the lockingtips 137 from the first and second doors 22 and 24 thereby allowing thedoors 22 and 24 to open. Each door 22 and 24 can have a frictionaldamper associated therewith to ensure a smooth opening process.

Additionally, a vertical locking rod 102 can be coupled to the lateralaxle 100 by a pivot rod 104 such that the vertical locking rod 102 canbe reciprocated upwardly and downwardly by a rotation of the lateralaxle 100. The vertical locking rod 102 can have a pivotally retainedproximal L-shaped actuator 108 with an engaging tip 112 proximallycoupled thereto and a pivotally retained distal L-shaped actuator 110with an engaging tip 114 distally coupled thereto. Also, looking againto FIGS. 7 and 8, the trolley structure 42 can have a locking projection116 projecting dorsally therefrom.

The trolley structure 42 can be selectively locked in a retractedconfiguration by an engagement of the engaging tip 114 of the distalL-shaped actuator 110 with the locking projection 116. Similarly, thetrolley structure 42 can be selectively locked in an extendedconfiguration by an engagement of the engaging tip 112 of the proximalL-shaped actuator 108 with the locking projection 116. The trolleystructure 42 can be released from each position by a simple actuation ofthe trigger 88 to cause the respective tip 112 or 114 to pivot out ofengagement with the locking projection 116. The lock 94, which can beoperated by a key 92 or any other effective arrangement, can selectivelyprevent operation of the trigger 88.

Use of an embodiment of a non-motorized extension and retractionarrangement 10 as in FIG. 4 with a manual actuation arrangement 90 as inFIG. 10 can be initiated by a pivoting or other actuation of the trigger88. With a sufficient pivoting of the trigger 88, the actuating rod 132can induce a pivoting of the L-shaped actuator 133 thereby to releasethe first and second doors 22 and 24 as the locking tips 137 are drawnout of engagement therewith. The spring-loaded disc portions 96 and 98can then smoothly pivot the first and second doors 22 and 24 to an openconfiguration. Simultaneously, the rotation of the lateral axle 100 canproduce a vertical displacement of the vertical locking rod 102 therebyto pivot the engaging tip 114 of the distal L-shaped member 110 out ofengagement with the locking projection 116 of the trolley structure 42.The trolley structure 42 is thus released from its retracted position.

Where the constant force springs 78 and 80 are calibrated to produce anet lifting force, the trolley 40, support arm 54, and the monitor 12can then automatically rise to an extended position as in FIG. 1. Themeans for providing a braking and cushioning effect, whether in the formof an arcuate braking member 148, a compression spring 152, or any otherform, can enable a smooth and controlled stopping of the travel of thetrolley structure 42 and the retained monitor 12 or other article. Theengaging tip 112 of the proximal L-shaped actuator 108 can then engagethe locking projection 116 of the trolley structure 42 thereby lockingthe monitor 12 and the trolley structure 42 in an extendedconfiguration.

The first and second doors 22 and 24 can then be adjusted to a closedconfiguration as in FIG. 1 to prevent debris from passing through theaperture 15 in the support structure 500 and to achieve a finishedappearance. It will be noted that providing first and second doors 22and 24 as compared to just a single door can be considered to beadvantageous for a number of reasons. For example, with first and seconddoors 22 and 24, the monitor 12, and consequently the support arm 54 andthe trolley 42, can be raised to a reduced height to gain clearancerelative to the doors 22 and 24 than would be required if just a singledoor were provided. Since the height to which the monitor 12 must beraised directly affects the required length of the first and secondrails 36 and 38 and the subsurface enclosure in general 16, theprovision of first and second doors 22 and 24 enables the extension andretraction arrangement 10 to be rendered more efficient and compact.Furthermore, the first and second doors 22 and 24 enable the armaperture 25, and thus the support arm 54, to be centrally disposed inrelation to the aperture 15 and the extension and retraction arrangement10.

When the monitor 12 is to be lowered, the trigger 88 can again beactuated to reopen the doors 22 and 24 and to release the engaging tip112 of the proximal L-shaped actuator 108. The monitor 12, support arm54, and the trolley structure 42 can be pressed to a retracted positionand locked there by the engaging tip 114 of the distal L-shaped actuator110. The doors 22 and 24 can be pressed closed and retained there by anengagement with the locking tips 137.

A variation of the manual actuation arrangement 90 is shown in FIG. 12.There, engaging tips 112 and 114 are again provided for selectivelyengaging and retaining the locking projection 116 of the trolleystructure 42. However, the L-shaped actuators 108 and 110 insteadcomprise rotatably retained disc-shaped actuators 108 and 110.Furthermore, a pivot gearing arrangement 106 is instead employed toinduce a reciprocation of the vertical locking rod 102 in response to anactuation of the trigger 88.

As the embodiment of FIG. 5 makes clear, the extension and refractionarrangement 10 can alternatively be motorized. An example of a motorizeddrive and actuating arrangement 140 is shown in FIG. 11. A drive motor118 can be fixed relative to the trolley structure while a rack gear 122can be fixed relative to the spine 40 and the first and second rails 36and 38 shown, for example, in FIG. 7. A pinion gearing arrangement 120can drivingly engage the drive motor 118 with the rack gear 122. Asecondary motor 124 can be drivingly associated with a lateral rod 130by a gearing arrangement 128. The lateral rod 130 can in turn bedrivingly engaged with door driving rods 132 by a worm gear arrangement134. The door driving rods 132 can engage the first door 22 by a geararrangement 126 between the door driving rods 132 and geared discportions 96 of the first door 22. Similarly, the door driving rods 132can engage the second door 24 by a gear arrangement 125 between the doordriving rods 132 and geared disc portions 98 of the second door 24.Constant force springs 78 and 80 as shown in FIG. 7 may or may not beincluded to provide a counterbalancing force in relation to the trolleystructure 42, the monitor 12, and the support arm 54.

A lock 94 and key 92 combination can enable access and control of theextension and retraction arrangement 10. Alternatively or additionally,as shown in relation to the alternative embodiment of FIG. 17, accessand control of the extension and retraction arrangement 10 could becontrolled by a card reader 172 in combination with an access card 170.The access card 170 could be of any suitable type including, by way ofexample, a dedicated security card, an identification card, a creditcard, a purchased card, or any other type of access card 170. Stillfurther, access and control could be had by operation of a remotecontrol unit 174 in combination with a receiver 176 as is also shown inFIG. 11.

Actuation of the motorized drive and actuating arrangement 140 of FIG.11 can induce the secondary or door motor 124 into operation thereby torotate the lateral rod 130 with a resultant rotation of the door drivingrods 132 and an opening of the doors 22 and 24 as the disc portions 96and 98 are driven by the gearing arrangements 126 and 125.Simultaneously with, before, or after, the opening of the doors 22 and24, the drive motor 118 can be induced into operation thereby to causeit, the trolley structure 42, and the retained monitor 12 to climb therack gear 122 until an extended disposition is reached as may be sensedby an upper limit switch 127 or other means. The first and second doors22 and 24 can then be closed by the secondary motor 124.

When the monitor 12 or other article is to be retracted, the lock 94 andkey 92, the card reader 172 and access card 170, the trigger 88, theremote control unit 174 and receiver 176, or any other means can beemployed to induce the secondary motor 124 into operation to open thedoors 22 and 24. The drive motor 118 can then be actuated to propel thetrolley structure 42, the monitor 12, and the support arm 54 to aretracted configuration. The doors 22 and 24 can then be closed byoperation of the secondary motor. Of course, one skilled in the artwould find it readily obvious and within the scope of the invention toemploy a single motor or more than two motors for opening the doors 22and 24 and raising and lowering the trolley structure 42.

An alternative extension and retraction arrangement is again indicatedat 10 in FIG. 18. The extension and retraction arrangement 10 has asupport base 184 relative to which a pair of cylindrical support rods186 and 188 are mounted in parallel spaced orientation relative to oneanother. Distal ends of the cylindrical support rods 186 and 188 aremounted on a lower support bracket 190. A trolley structure 42 isslidably engaged with the support rods 186 and 188.

The trolley structure 42 in this embodiment includes opposing bushings192 and 194 that slide along the support rods 186 and 188. Bearings 196,198 provide smooth gliding engagement between the bushings 192 and 194and the support rods 186 and 188. Threaded mounting holes 145 are againformed in the trolley structure 42 in accordance with the VideoElectronics Standards Association Flat Display Mounting Standard forflat panel monitors. Constant force springs 78 and 80 are rotatablyretained relative to the support base 184 and have distal ends connectedto the trolley structure 42.

To prevent damage to the monitor 12 as it reaches an extended position,rubber o-rings 200 and 202 mounted on the upper or proximal ends of thesupport rods 186 and 188 provide shock absorption for the trolleystructure 42. A lock 94 and key 92 combination or other means cancontrol access and operation of the extension and retraction arrangement10 to prevent unauthorized access to the monitor 12 or other supportedarticle. The lock 94 can prevent rotation of the lateral axle 100 untilthe key 92 or other means is actuated.

As shown in FIG. 17, the raising and lowering of the trolley structure42 can be driven by a motor 182 that drives a pinion gear 180 along arack gear 178. The rack gear 178 can be disposed along a support rod 188or otherwise disposed, such as along a subsurface enclosure (not shown).As previously described, access and control can additionally becontrolled by a card reader 172 and access card 170 and, additionally oralternatively, a remote control unit 174 and receiver 176. Such anextension and retraction arrangement 10 can be employed with or withoutconstant force springs 78 and 80.

With reference to FIG. 19, one sees that a braking arrangement can againbe provided. The braking arrangement can again include an arcuatebraking member 148 and a braking screw 150 for adjusting the brakingforce to be applied. The braking member 148 can have a first end fixedin relation to the support base 184 and a free body portion.

Extension and retraction arrangements 10 can be supplied with a supportstructure 500, such as the desk in FIGS. 1 through 3, as originalequipment. Alternatively, extension and retraction arrangements 10 canbe supplied in retrofit kit form. As one can perceive from FIG. 6, sucha kit could include the extension and retraction arrangement 10,mounting fasteners 35, and a template 33 for cutting an aperture 15 in asupport structure 500 in which it is to be installed. With an extensionand retraction arrangement 10 installed in relation to a supportstructure, whether before or after sale to the ultimate consumer, amonitor 12 can be readily mounted to the support arm 54. The supportstructure 500, the extension and retraction arrangement 10, and themonitor 12 can be sold integrated together. Alternatively, the monitor12 and an extension and refraction arrangement 10 can be sold as apackage.

With reference to FIGS. 20 and 21, an extension and retractionarrangement 10 is depicted that not only extends and retracts anarticle, such as a monitor 12, but also enables an adjustment of theposition, orientation, and location of the monitor 12 by use of a springbalanced arm arrangement 205. The spring balanced arm arrangement 205can have an arm 204 that can be pivotally coupled to the trolleystructure 42 at a proximal pivot axis 206. The monitor 12 can bepivotally coupled to the arm 204 at a distal pivot axis 208. The arm 204can include first and second arm portions 204A and 204B and can bebalanced by one or more springs 214. Additionally, the arm 204 canrotate about a vertical axis relative to the support structure 500 by arotation of a pivot rod 210 that projects from the proximal pivot axis206 and is received into a pivot aperture 212 in the trolley structure42.

In FIG. 22, the spring balanced arm 205 can be articulated with a firstarm 216 pivotally coupled at a proximal end to the trolley structure 42and a distal end pivotally coupled to a proximal end of a second arm218. The monitor 12 can be pivotally coupled to the monitor 12 by amonitor mounting bracket 220. The first arm 216 can be formed by spacedfirst and second arm portions 204A and 204B, and the second arm 218 canbe pivoted to be disposed inboard of the first and second arm portions204A and 204B to enable a most compact storage of the spring balancedarm 205.

As noted previously, extension and retraction arrangements 10 under thepresent invention can be employed relative to numerous different typesof support structures 500, not only desks. For example, turning to FIG.23, an extension and refraction arrangement 10 is retained relative to asupport structure 500 comprising a slot wall arrangement. The slot wallarrangement can have a wall portion 502 and, possibly, a desk portion504. The subsurface enclosure 16 and the extension and retractionarrangement 10 in general can be secured relative to a slot 222 in thewall portion 502 to enable the monitor 12 and support arm 54 to beextended from the subsurface enclosure 16, possibly through the deskportion 504. Alternatively, the subsurface enclosure 16 of the extensionand retraction arrangement 10 can be disposed within a wall portion 502,which may or may not be a slot wall. In certain cases, for example, thewall portion 502 can comprise a typical office partition wall or anyother type of wall.

Yet another embodiment of the extension and retraction arrangement 10 isdepicted in FIGS. 24A and 24B. There, a computer central processing unit224 is retained within the subsurface enclosure 16 for interaction withthe monitor 12, a keyboard 230, and any further computer components thatmay be required. Furthermore, one or more computer drive units 226 canbe incorporated into the extension and retraction arrangement 10, suchas in relation to the upper framework 14 as in FIGS. 24A and 24B. Withthis, the extension and retraction arrangement 10 could house oressentially comprise a self-enclosed computer system.

In certain practices of the invention, a keyboard 230 can additionallyor alternatively be retained for extension and refraction. As shown inFIGS. 24A and 24B, for example, a keyboard 230 can be retained relativeto the support arm 54, and thus relative to the trolley structure 42(not shown in FIGS. 24A and 24B) by a keyboard cradle 228. The keyboardcradle 228 could be fixed in relation to the support arm 54 or pivotableby use of a pivot arrangement 232. The keyboard 230 can be used whileretained in relation to the keyboard cradle 228, or it can be removableas in FIG. 24B.

A further refined embodiment of an extension and retraction arrangement10 according to the present invention is depicted in FIGS. 25 and 26 andvarious subassemblies and components thereof are shown in FIGS. 27through 33. In FIG. 25, the extension and retraction arrangement 10 canbe seen to have an upper flange formed by a modesty cover 26A incombination with a flush mount modesty cover 26B. A rectangular topcover 234 is received within a correspondingly shaped and sizedrectangular opening defined by the flush mount modesty cover 26A.

The top cover 234 has a rectangular aperture therein. A centrallydisposed, rectangular notch in an inner edge of the top cover 234 to theventral side thereof forms an arm aperture portion 25A. The arm apertureportion 25A cooperates with a correspondingly disposed arm apertureportion 25B in a central portion of a distal, ventral end of a sliding,articulated door 242. With this, when the articulated door 242 is in aclosed position as in FIG. 26, the arm aperture portions 25A and 25Bmeet to form an arm aperture 25 through which the support arm 54 can bereceived while the support arm 54 is an extended position.

As shown in FIG. 26, a flipper door 236 and a pocket door 238 cooperateto seal the arm aperture 25 entirely when the support arm 54 and aretained trolley 42 are in a refracted position. As describedhereinbelow, the flipper door 236 and the pocket door 238 can pivot toan open position with the flipper door 236 pivoting upwardly and thepocket door 238 pivoting downwardly to open the arm aperture 25 andthereby to permit a receiving of the support arm 54 while the trolley 42and the support arm 54 are extended.

Looking to FIG. 27, the flipper door 236 is pivotally retained byretaining members 240 that are affixed to or integrated within the upperframework 14. More particularly, the flipper door 236 has pivot rodsthat project outboard from opposed first and second ends thereof. Thepivot rods establish an axis of rotation for the flipper door 236 andare received into corresponding apertures in the retaining members 240.The axis of rotation of the flipper door 236 is generally aligned withthe edge of the arm aperture portion 25A in the top cover 234. Withthis, the flipper door 236 closes the arm aperture portion 25A when theflipper door 236 is in a closed disposition.

The flipper door 236 can pivot upwardly, such as when contacted by thetip of the support arm 54, so that the flipper door 236 rests againstthe support arm 54 when the arm 54 is in a raised position. The flipperdoor 236 can automatically pivot to a closed position when the supportarm 54 retracts. While this automatic pivoting could be accomplished ina number of ways, the present embodiment ensures an automatic pivotingby force of gravity. To facilitate this, flipper arms 237 projectradially from the pivot rods 236 angularly spaced therefrom to bedisposed below the flipper door 236, more particularly projectinggenerally vertically downwardly, when the flipper door 236 is disposedin a closed, horizontal disposition generally coplanar with the topcover 234.

Under this arrangement, the flipper arms 237 thus act as an eccentricweight relative to the axis of rotation of the flipper door 236. Stops239 are fixed to the retaining members 240, such as by being integrallyformed therewith, such that the stops 239 are fixed in place relative tothe upper framework 14. With this, the flipper door 236 is permitted topivot until it reaches an orientation generally coplanar with the topcover 234 whereupon the flipper arms 237 contact the stops 239 therebyto prevent further pivoting and to maintain the closed position of theflipper door 236. The flipper door 236 is thus biased to a closedposition by the weight of the flipper arms 237 and prevented frompivoting past the closed position by the contacting of the flipper arms237 with the stops 239.

The pocket door 238 is pivotally retained relative to the articulateddoor 242 to close the arm aperture portion 25B when in a closedposition. The pocket door 238 has an axis of rotation disposed inalignment with the edge of the arm aperture portion 25B whereby thepocket door 238 is generally coplanar with the first door section 244 ofthe articulated door 242 when the pocket door 238 is in a closedposition. The pocket door 238 can pivot downwardly to an open positionto allow the support arm 54 to be received in the arm aperture portion25B. The pocket door 238 can be biased, such as by one or more springs,by eccentric weighting, or by any other means, to a closed positiongenerally coplanar with the first door section 244. The pocket door 238is prevented from pivoting passed the closed position by havingoutboard, offset edges that underlie side, offset edges of the armaperture portion 25B. The complementary offset edges of the pocket door238 and the arm aperture portion 25B permit the pocket door 238 and thefirst door section 244 to present a substantially flat surface.

The pocket door 238 and the flipper door 236 can lock in relation to oneanother when the articulated door 242 is in a closed position. In oneexample, a distal portion, such as an offset distal edge, of the pocketdoor 238 can be disposed to overlap a distal portion, such as an offsetdistal edge, of the flipper door 236 when the articulated door 242 is ina fully closed position. With this, where the flipper door 236 ispivotable upwardly but not downwardly passed a closed position, thepocket door 238 is pivotable downwardly but not upwardly passed a closedposition, and the doors 236 and 238 are engaged, the flipper arms 237 ofthe flipper door 236 will engage the stops 239 to prevent the flipperdoor 236 from pivoting downwardly, the overlapping edges of the pocketdoor 238 and the flipper door 236 will prevent the pocket door 238 frompivoting downwardly, and the doors 236 and 238 can present asubstantially flat surface. With this, the arm aperture 25 will beeffectively sealed when the support arm 54 is disposed in a storagedisposition.

The structure and operation of the articulated door 242 can be betterunderstood with additional reference to FIGS. 28 and 29. The articulateddoor 242 is slidable from the closed position of FIG. 26, to an openposition for allowing the extension and retraction of the support arm 54and the trolley 42, and again to a closed position with the support arm54 in a raised position received through the arm aperture 25 with thedoors 236 and 238 in open dispositions.

The articulated door 242 is formed by multiple sections pivotallycoupled along lateral pivot axes that facilitate its sliding extensionand retraction between open and closed positions. In the depictedembodiment, the door 242 is formed with first and second sections 244and 246 that are coupled to pivot along a lateral pivot axis. Of course,it would be possible to form the articulated door 242 with just onesection or with more than two sections. The first and second sections244 and 246 could be coupled by any pivotal coupling means. In thiscase, the pivotal coupling means comprises a hinge pin 248, but a livinghinge or any other means could readily be employed.

The articulated door 242 is propelled and guided by door pathsubassemblies 254A and 254B respectively disposed to the first andsecond sides of the articulated door 242. As can be perceived from FIG.29 where a door path subassembly 254A is shown in an exploded view, eachdoor path subassembly 254A has a door path cover 268 secured to anoutboard side of a door path guide member 270 as by fasteners or anyother suitable means or combination thereof. The door path guide member270 has a drive slot 280, which in this embodiment is disposed entirelytherethrough. The drive slots 280 of the door path subassemblies 254Aand 254B slidably receive distal drive pins 284 that project laterallyfrom opposed sides of the first door section 244 adjacent to the distaledge of the first door section 244.

The first and second door sections 244 and 246 additionally have centraland proximal slide pins 286 and 288 projecting laterally outwardly fromeach side of the door 242 at a mid-portion and proximal end of thearticulated door 242 respectively. The central slide pins 286 projectlaterally outwardly from adjacent to the proximal edge of the first doorsection 244, and the proximal slide pins 288 project laterally outwardlyfrom adjacent to the proximal edge of the second door section 246 andthus from the adjacent to the proximal edge of the articulated door 242in general. It can be seen that the distal drive pins 284 are longerthan the central and proximal slide pins 286 and 288. With this, thecentral and proximal slide pins 286 and 288 can fit between the basepanels of the door path guide members 270 while the distal drive pins284 can project through the drive slots 280 in the door path guidemembers 270.

To the inboard side of each door path guide member 270 is an arcuateguide surface 282, which can be best seen in FIG. 25. The arcuate guidesurfaces 282 provide smooth surfaces over which the slide pins 286 and288 can travel during movement of the articulated door 242 between openand closed positions. Each arcuate guide surface 282 has a proximalportion disposed generally vertically, a distal portion disposedgenerally horizontally and parallel to the drive slot 280, and anarcuate portion connecting the proximal and distal portions.

The articulated door 242 is driven between open and closed positions bya flexible drive belt 274. The drive belt 274 has an eye aperture 275 atthe distal end thereof for receiving the drive pins 284 that projectoutboard from adjacent to the distal end of the first door section 244.The drive belt 274 has teeth 277 therealong for enabling it to be drivenby a gear 272, which in turn is rotated by a gear 256A disposed at adistal end of the drive rod 130. A corresponding drive gear 256B isdisposed at the opposite end of the drive rod 130 to actuate the drivebelt 274 of the door path subassembly 254B

With further reference to FIG. 28, the drive rod 130 is rotated byoperation of the door motor 124 through first and second gears 128A and128B. The motor 124 is supported by a mounting bracket 129 disposed atopa damping pad 131, and the drive rod 130 is retained by a plurality ofshaft supports 258. With this, the articulated door 242 can be smoothlymoved between closed and open positions by an actuation of the motor124, which will rotate the drive rod 130 to cause a rotation of the gear272. The rotation of the gear 272 will cause a longitudinal movement ofthe eye aperture 275 of the drive belt 274. With the drive pin 284received through the eye aperture 275 at the distal end of the drivebelt 274, the door 242 will undergo a sliding movement. The drive pin284 will travel along the drive slot 280, and the slide pins 286 and 288will slide along the arcuate guide surface 282, which has a straightdistal portion generally parallel to the drive slot 280.

When the articulated door 242 is in a closed position, the first andsecond door sections 244 and 246 are disposed generally coplanar withone another and with a surrounding work surface. As the articulated door242 travels to an open position, the door 242 slides away from the topcover 234 to provide an aperture through which the arm 54 and anyretained monitor 12 or other retained article can pass. The distal edgeof the first door section 244 maintains a substantially consistentheight as the drive pins 284 slide along the drive slots 280. The seconddoor section 246 and the proximal portion of the first door section 244travel downwardly as the slide pins 286 and 288 slide along the arcuateguide surface 282.

As seen in FIG. 29, closed and open sensors 276 and 278, which mayalternatively be referred to as switches 276 and 278, are incorporatedinto the extension and retraction arrangement 10 for sensing when thearticulated door 242 has reached its fully closed and fully openpositions respectively. In this embodiment, the sensors 276 and 278 areretained within one or both door path subassemblies 254A and 254B. Whena closed position is reached, the closed sensor 276 can be contacted bythe articulated door 242, the drive belt 274, or otherwise to induce atermination of the operation of the motor 124. Similarly, when an openposition is reached, the open sensor 278 can be contacted to induce atermination of the operation of the motor 124.

Looking again to FIG. 26, one can see that a subsurface enclosure 16 canbe formed by a left casing 16A, a right casing 16B, a casing cover 16C,and a bottom structure 16D together with the spine member 40, which canactually form a portion of the subsurface enclosure 16. The left andright casings 16A and 16B, the casing cover 16C, the bottom structure16D, and the spine member 40 can be joined by any suitable meansincluding mechanical fasteners, mechanical engagement as byinterlocking, welding, or any other method or combination thereof.

The trolley 42, which retains a support arm 54, can again communicatelongitudinally between raised and lowered positions, such as by slidingor the rolling of wheels as described previously or otherwise, along thespine member 40. A support plate 144 is pivotally retained at the distalor upper end of the support arm 54 for retaining a monitor 12 (not shownin FIGS. 26 and 30). The raising and lowering of the trolley 52, thesupport arm 54, and any retained monitor 12 can be accomplished by amotor 118 that is mounted to the combined trolley 42 and arm 54 to movetherewith. The motor 118 rotates a pinion gear 120 that travels along arack gear 122 retained by or directly formed in the spine member 40 asshown in FIG. 26.

Depicted in FIG. 26, a lower limit switch 139 or other sensor means cansense when the trolley 42 has reached its fully lowered position, and anupper limit switch 127 or other sensor means can sense when the trolley42 reaches its fully raised position. The upper and lower limit switches127 and 139 can be mounted to the spine 40 as shown or otherwiseretained relative to the subsurface enclosure 16 to sense the upper andlower positions of the trolley 42. It would alternatively be possible toretain a sensor or sensors to move with the trolley 42 to sense upperand lower terminal positions relative to the subsurface enclosure 16.

As shown in FIG. 30, a monitor position sensor 264, which canalternatively be termed a switch, is supported by a safety switchsupport 262 and is backed by a safety switch cover 266. The motionposition sensor 264 is contacted or compressed by the support plate 144when the support plate 144 is in a fully upright position. So disposed,the monitor position sensor 264 senses whether the support plate 144 andthus a retained monitor 12 are upright and thus ready to be retracted ora position away from upright and thus not prepared for retraction.

Looking again to FIG. 25, a switch button insert subassembly 252 isreceived into and retained by a first end of the upper framework 14, andan insert 250 is received into a second end of the upper framework 14.The switch button subassembly 252, which is shown in an exploded view inFIG. 31, has a casing 290 that receives an insert cap 292 and a wire cap284. An UP button 296 and a DOWN button 298 are retained relative to acircuit board 300, which is secured to an insert cover 302. The UP andDOWN buttons 296 and 298, the upper and lower limit switches 127 and139, the monitor position sensor 264, the motors 118 and 124, andfurther electrical components of the arrangement 10 can beelectronically coupled, whether via wires, wirelessly, or a combinationthereof, to a power control box 260. While the UP and DOWN buttons 296and 298 are depicted as physically incorporated into the framework 14,it is certainly within the scope of the invention to provide a remotecontrol unit 174 as shown in FIG. 11.

Embodiments of the extension and retraction arrangement 10 canadditionally incorporate a lock subassembly, which is shown in FIG. 32in an exploded configuration and assembled in FIG. 33. The locksubassembly is founded on a casing 304, which can be incorporated intothe insert 250 or otherwise disposed. An LED insert cap 306 is receivedinto and retained by the casing 304. A mechanical lock 94 is receivedinto the casing 304, and a toggle switch 310 is retained on a circuitboard 312. An LED 308 is electrically coupled to the toggle switch 310,and a supplemental circuit board 318 is secured relative to the casing304. The mechanical lock 94 actuates a plate lock member 314, whichactuates an activator plate 316. A lock insert cover 320 and an insertwiring cover 322 enclose the open inner volume of the casing 304.

The installation and operation of extension and retraction arrangements10 according to the present invention can be governed and controlled bya motion control system. The motion control system is designed to ensurethat the trolley 42, the support arm 54, and any retained monitor 12rise and lower and that the articulated door 242 opens and closesreliably, safely, and effectively. The motion control system can governand control the installation and operation of a single extension andretraction arrangement 10 or a plurality of extension and refractionarrangements 10 functionally interconnected, such as in series or inparallel, wired or wirelessly.

When appropriate, such as on initial installation of the arrangement 10,replacement of the monitor 12, or after repair, the arrangement 10 canbe placed in an installation mode, such as automatically or by a controlswitch 265 or other means electrically associated with the power controlbox 260 and disposed on the insert 250 or elsewhere. In addition to thesetting of the switch 265, the installation mode can be indicated by theactuation or non-actuation of an indicator light 267. The control switch265 and the indicator light 267 could alternatively elsewhere, such ason the power control box 260 and rendered accessible through or fromexterior to the subsurface enclosure 16.

When the arrangement 10 is adjusted to or otherwise disposed ininstallation mode, the motion control system allows the trolley 42 to goup only once, such as in response to the UP button 296 being pressed.The DOWN button 298 is inoperable when the arrangement 10 is ininstallation mode. Once the trolley 42 reaches a fully raised positionas sensed by the upper limit switch 127, the arrangement 10 will shutdown. Under this shutdown status, the arrangement 10 will not operateeven upon a pressing of the UP or DOWN buttons 296 and 298. If a monitor12 was not already in place, the monitor 12 can then be attached to thesupport plate 144 while the support arm 54 is raised.

After the trolley 42 is raised and the upper limit switch 127 is trippedindicating successful installation, the user can switch the arrangement10 to operation mode, again potentially by use of the control switch265. The indicator light 267 can provide an indication of theoperational mode status. The user can then press the UP button 296,which will cause the raising procedure to complete with the articulateddoor 242 sliding closed until the closed sensor 276 is tripped. Withthat, the arrangement 10 is rendered fully operational with the trolley42, the support arm 54, and any retained monitor 12 in a raisedposition. With the support arm 54 so disposed, the flipper door 236 andthe pocket door 238 are disposed in an open position, and the supportarm 54 is received through the aperture 25 such that an entirely sealedsurface is presented. Alternatively, the user can press the DOWN button298, which will cause the trolley 42 to travel to a down position whereit will come to a stop on actuation of the lower limit switch 139. Thearticulated door 242 will then be slid to a closed position, and thearrangement 10 is rendered fully operational with the articulated door242, the flipper door 236, and the pocket door 238 presenting asubstantially continuous surface.

With a monitor 12 properly installed and the arrangement 10 fullyoperational, there are two possibilities that should be accommodated.First, where the user adjusts the switch 265 to installation mode whilethe trolley 42 is in a raised position, the arrangement should notperform any functions. Such a situation might arise, by way of example,when an originally installed monitor 12 is being replaced. Second, theend user can adjust to installation mode while the trolley 42 and themonitor 12 are in a down position. In that case, the arrangement 10 willperform as programmed for installation mode as described above where thetrolley 42 will be brought to a fully raised position and the door 242will be left in an open position on a pressing of the UP button 296.Again, this may be warranted, for example, when the originally installedmonitor 12 is to be replaced.

During normal usage of the extension and retraction arrangement 10, themotion control system establishes a DOWN sequence of operation and an UPsequence of operation. In the DOWN sequence of operation, the trolley 42begins from a fully raised position with the articulated door 242 in aclosed position. The pressing of the DOWN button 298 will activate thedoor motor 124, which will slide the articulated door 242 to an openposition. Once the articulated door 242 reaches the open position asindicated by an engagement of the open sensor 278, the trolley motor 118is actuated to lower the trolley 42 toward a lowered position. Once thetrolley 42 triggers the lower limit switch 139, the door motor 124 willbe actuated to slide the articulated door 242 toward a closed position.Once the articulated door 242 reaches the closed position as indicatedby an engagement of the closed sensor 276, the door motor 124 will stopthereby placing the arrangement 10 in a closed or storage configuration.The flipper door 236 and the pocket door 238 will engage one another,and the arrangement 10 will be effectively sealed. When the trolley 42is in a lowered position, the DOWN button 298 will be disabled such thatpressing the DOWN button 298 will not send any signal through thearrangement 10.

In the UP sequence of operation where the trolley 42 begins from a fullylowered position, the end user can press the UP button 296. Pressing theUP button 296 will induce the door motor 124 into operation causing thearticulated door 242 to slide toward an open position. Once thearticulated door 242 reaches the open position as indicated by anengagement of the open sensor 278, the trolley motor 118 is actuated toraise the trolley 42 toward a raised position. As the trolley 42 and thesupport arm 54 rise, the flipper door 236 will be contacted and pivotedupwardly. Once the trolley 42 triggers the upper limit switch 127, thedoor motor 124 will be actuated to slide the articulated door 242 towarda closed position. As the door 242 slides to a closed position, thepocket door 238 will contact the support arm 54 and will pivotdownwardly. Once the articulated door 242 reaches the closed position asindicated by an engagement of the closed sensor 276, the door motor 124will stop thereby placing the arrangement 10 in a raised or useconfiguration. The support arm 54 will be received through the armaperture 25 with the flipper door 236 pivoted upwardly and restingagainst the support arm 54 and the pocket door 238 pivoted downwardly.When the trolley 42 is in a raised position, the UP button 296 will bedisabled such that pressing the UP button 296 will not send any signalthrough the arrangement 10.

The UP and DOWN sequences rely on the monitor 12 being fully upright asindicated by the support plate 144 contacting the monitor positionsensor 264. Where the monitor position sensor 264, which is interposedbetween the support plate 144 and the support arm 54, is not actuated asby being fully compressed or otherwise, all power to the arrangement 10will be cut thereby preventing potentially damaging operation while themonitor 12 is tilted away from an upright disposition. Consequently,where the monitor 12 and support plate 144 are in an angled dispositionthereby disengaging the monitor position sensor 264, power will not beallowed to flow through the arrangement 10 and the motors 118 and 124and other components will power down whether the trolley 42 is inmotion, in a raised position, or in a lowered position.

Where the trolley 42 is stopped while in motion, such as by adisengaging of the sensor 264, restarting the arrangement 10 under themotion control system can be carried out under a restarting procedure.The user will first adjust the monitor 12 to an upright position therebycausing the monitor position sensor 264 to be engaged. With that, thearrangement 10 will again permit the flow of power. The user can thenpress the UP button 296 causing the arrangement 10 to begin the UPsequence from the position the trolley 42 was in when the monitorposition sensor 264 was disengaged. The DOWN button 298 will be disabledsuch that pressing the DOWN button 298 will not induce any operation inthe arrangement 10.

The door motor 124 has a means for sensing current in excess of apredetermined value electrically associated therewith, such as by beingpart of the program built into the motion control system. Theover-current sensor senses a spike in amperage caused by an obstructionof the motion of the articulated door 242 or another malfunction of thedoor 242. When the amperage reaches a predetermined value, such as0.28-0.30 A in one embodiment of the arrangement 10, the sequence willbe stopped. Once the obstruction is removed, the user has the choice ofpressing the UP or DOWN buttons 296 or 298. If the user presses the UPbutton 296, the arrangement 10 and the door 242 in particular willcontinue the UP sequence from the position it was in before the currentspike. If the user presses the DOWN button 298, the arrangement 10 andthe door 242 will continue the down sequence from the position the door242 was in before the current spike.

The motion control system additionally provides capabilities foraccommodating power outages under each possible operating condition. Ifa power outage occurs while the trolley 42 is fully raised, the trolley42 will remain in the raised position when power is restored. Likewise,if a power outage occurs while the trolley 42 is in a fully lowereddisposition, the trolley 42 will remain in the lowered position whenpower is restored. If power fails while the trolley 42 is movingupwardly, the user can press the UP button 296 once power is restored tocause the arrangement 10 to begin the UP sequence from the position thetrolley 42 was in when the power failed. The DOWN button 298 will bedisabled such that pressing the DOWN button 298 will not induce anyoperation in the arrangement 10. Where there is a power failure whilethe trolley 42 is being lowered, the user can press the UP button 296once power is restored to cause the arrangement 10 to begin the UPsequence from the position the trolley 42 was in when the power failed.The DOWN button 298 will be disabled such that pressing the DOWN button298 will not induce any operation in the arrangement 10. Finally, ifthere is a power failure while the trolley 42 is being raised while ininstallation mode, the user can press the UP button 296 once power isrestored to cause the arrangement 10 to begin the UP sequence in theinstallation mode from the position the trolley 42 was in when the powerfailed. Again, the DOWN button 298 will be disabled such that pressingthe DOWN button 298 will not induce any operation in the arrangement 10.

The extension and retraction arrangement 10 can have an on/off switch269, which could be disposed on the control box 260, on the insert 250as shown in FIG. 26, or elsewhere. The on/off switch 269 gives the userthe ability to control the passage of power from a power source to thepower control box 260 and the arrangement 10 in general. Permitting thearrangement 10 to be powered off when not in use without affecting thesurrounding environment gives added control over the arrangement 10 andsignificantly improves the life of the electronic components of thearrangement 10. When the on/off switch 269 is in an ON position, thepower control box 260 will receive constant power, and, when the switch269 is in an OFF position, the power control box 260 will not receiveany power and will not function. In all operating conditions, thearrangement 10 will react to power being shut off via the power switch269 as it would if power were unintentionally interrupted due to a poweroutage, power surge, or the like.

The trolley motor 118 and power control box 260 additionally incorporatea means for sensing excess current that acts as a component of themotion control system to protect the arrangement 10 from an overloadwhile the trolley 42 is in motion. If there is an obstruction to themovement of the trolley 42 while it is in motion, the motion controlsystem will stop the trolley 42 when the over-current sensor senses acurrent equal to or greater than a predetermined value, such as 0.68 Ain one contemplated embodiment, which is designed to correspond to 15 KGto 20 KG weight of obstruction. Once the trolley 42 is stopped, allpower to the arrangement 10 will be shut down. Once the obstruction isremoved, the user can press the UP button 296. The arrangement 10 willthen follow the UP sequence from the position it was in before thecurrent spike. The DOWN button 298 will be disabled such that pressingit will not induce any operation of the arrangement 10.

The arrangement 10 can further include a fuse resistor within the powercontrol box 260. When tripped, the fuse resistor stops the electricaland mechanical functions of the arrangement 10 to avoid damaging othercomponents. The fuse resistor can be soldered to the pc board of thepower control box with legs that raise the fuse resistor off of the pcboard to keep the fuse resistor out of direct contact with all othercomponents. In one contemplated embodiment, the fuse resistor is ratedat 0.7 A.

There are three conditions, which are described as conditions A, B, andC below, where the trolley 42 will refuse to function or will stopfunctioning in the middle of a sequence. No matter which conditions A,B, or C under which the trolley 42 stops, the arrangement 10 willfunction the same once it is returned to operative condition and theuser presses the UP button 296. Under a fourth condition, which isdescribed as condition D below, the arrangement 10 will permit the userto press the UP or DOWN buttons 296 or 298 to induce the UP or DOWNsequences once the arrangement 10 is returned to the operativecondition.

In condition A, the monitor position sensor condition, the arrangement10 can be assumed to have the trolley 42 in a raised disposition and thearticulated door 242 in a closed position. When the user presses theDOWN button 298, the door 242 will be opened. Once the door open sensor278 is engaged, the trolley motor 118 will be actuated to move thetrolley 42 toward the lowered position. When the trolley 42 is partlylowered, the monitor position sensor 264 becomes disengaged. Power tothe motor 118 is cut, and the trolley 42 immediately stops. When themonitor position sensor 264 is re-engaged, the trolley 42 will be idle.The DOWN button 296 is inoperable. The user can induce operation only bypressing the UP button 298, which will cause the arrangement 10 tofollow the UP sequence with the trolley 42 moving to a raised positionand the door 242 then sliding to a closed position.

Under condition B, the trolley motor over-current sensor protectioncondition, the arrangement 10 can be assumed to have the trolley 42 in alowered disposition and the articulated door 242 in a closed position.When the user presses the UP button 298, the articulated door 242 willbe moved to an open position. Once the door open sensor 278 is engaged,the trolley motor 118 will be actuated to move the trolley 42 toward theraised position. During the upward travel of the trolley 42, anobstruction hampers further motion of the trolley 42. When the trolleymotor over-current sensor senses the predetermined current spike, suchas to 0.68 A, power to the trolley motor 118 will be terminated, and thetrolley 42 will stop. Once the obstruction is removed, the user canpress the UP button 298, which will cause the arrangement 10 to followthe UP sequence with the trolley 42 traveling to a raised position andthe door 242 then sliding to a closed position. The DOWN button 296 isinoperable.

Under condition C, the power outage condition, the arrangement 10 can beassumed to have the trolley 42 in a raised disposition and thearticulated door 242 in a closed position. When the user presses theDOWN button 296, the articulated door 242 will be moved to an openposition. Once the door open sensor 278 is engaged, the trolley motor118 will be actuated to move the trolley 42 toward the lowered position.During the downward travel of the trolley 42, a power failure stops themotion of the trolley 42. Once the power is returned, the user can pressthe UP button 298, which will cause the arrangement 10 to follow the UPsequence with the trolley 42 traveling to a raised position and the door242 sliding to a closed position. The DOWN button 296 is inoperable.

In condition D, the door motor over-current sensor condition, thearrangement 10 can be assumed to have the trolley 42 in a raiseddisposition and the articulated door 242 in a closed position. When theuser presses the DOWN button 298, the door 242 will begin to open. Asthe door 242 is opening, an obstruction prevents further movement andthe door motor over-current sensor senses the predetermined currentspike whereupon power to the door motor 124 is terminated and the door242 stops. Once the obstruction is removed, the user can press the UPbutton 298 or the DOWN button 296. If the UP button 298 is pressed, thedoor 242 will begin to close and will continue until the door closedsensor 276 is triggered, and the trolley 42 does not move. If the DOWNbutton 296 is pressed, the door 242 will begin to open and will continueuntil the door open sensor 278 is triggered. The arrangement 10 willcontinue to follow the down sequence with the trolley 42 moving to alowered position and the door 242 then sliding to a closed position.

With certain details of the present invention for a motion controlsystem for an extension and retraction arrangement disclosed, it will beappreciated by one skilled in the art that changes and additions couldbe made thereto without deviating from the spirit or scope of theinvention. This is particularly true when one bears in mind that thepresently preferred embodiments merely exemplify the broader inventionrevealed herein. Accordingly, it will be clear that those with certainmajor features of the invention in mind could craft embodiments thatincorporate those major features while not incorporating all of thefeatures included in the preferred embodiments.

Therefore, the following claims are intended to define the scope ofprotection to be afforded to the invention. Those claims shall be deemedto include equivalent constructions insofar as they do not depart fromthe spirit and scope of the invention. It must be further noted that aplurality of the following claims may express certain elements as meansfor performing a specific function, at times without the recital ofstructure or material. As the law demands, these claims shall beconstrued to cover not only the corresponding structure and materialexpressly described in this specification but also all equivalentsthereof that might be now known or hereafter discovered.

1. An extension and retraction arrangement with a control system for adjusting a monitor from a retracted configuration to an extended configuration, the extension and retraction arrangement comprising: a trolley structure; a means for retaining a monitor to travel with the trolley structure; an elongate support arrangement with a first end, a second end, and a body portion between the first and second ends; a means for retaining the trolley structure for axial extension and retraction along the body portion of the elongate support arrangement from adjacent to the first end to adjacent to the second end of the elongate support arrangement; a means for propelling the trolley structure to travel along the body portion of the elongate support arrangement; a framework fixed adjacent to the second end of the elongate support arrangement wherein the framework has a centrally disposed aperture wherein the monitor projects through the aperture in the framework when the trolley structure is disposed adjacent to the second end of the elongate support arrangement; a door with an open position and a closed position for at least partially closing the aperture in the framework; a means for propelling the door between an open position and a closed position; a control system for controlling the extension and retraction of the trolley structure and an opening and closing of the door wherein the control system has an operation mode with an UP sequence and a DOWN sequence, wherein the extension and retraction arrangement has a storage configuration with the door in a closed position and the trolley structure and the monitor disposed below the door, and wherein the extension and refraction arrangement has a use configuration with the monitor extended beyond the door and the door in a closed position; and a means for enabling a user to induce the UP sequence and the DOWN sequence; wherein the UP sequence of the control system comprises adjusting the door to an open position, propelling the trolley structure and the monitor to an extended disposition with the monitor disposed beyond the aperture in the framework, and adjusting the door to a closed position to achieve the use configuration and wherein the DOWN sequence of the control system comprises adjusting the door to an open position, propelling the trolley structure and the monitor to a refracted disposition with the monitor disposed below the aperture in the framework, and adjusting the door to a closed position to achieve the storage configuration.
 2. The extension and retraction arrangement of claim 1 wherein the control system further comprises an open sensor for sensing the open position of the door, a closed sensor for sending the closed position of the door, an upper limit sensor for sensing the extended disposition of the trolley structure and the monitor, and a lower limit sensor for sensing the retracted disposition of the monitor and the trolley structure.
 3. The extension and refraction arrangement of claim 2 wherein the UP sequence of the control system comprises adjusting the door to an open position until the open sensor is actuated, then propelling the trolley structure and the monitor to an extended disposition with the monitor disposed beyond the aperture in the framework until the upper limit sensor is actuated, and then adjusting the door to a closed position until the closed sensor is actuated to achieve the use configuration and wherein the DOWN sequence of the control system comprises adjusting the door to an open position until the open sensor is actuated, then propelling the trolley structure and the monitor to a retracted disposition with the monitor disposed below the aperture in the framework until the lower limit sensor is actuated, and then adjusting the door to a closed position until the closed sensor is actuated to achieve the storage configuration.
 4. The extension and retraction arrangement of claim 1 wherein the means for retaining the monitor to travel with the trolley structure comprises a support arm and further comprising an arm aperture portion in the door for receiving the support arm when the extension and retraction arrangement is in a use configuration.
 5. The extension and retraction arrangement of claim 4 further comprising a pocket door pivotally coupled to the door and a means for retaining the pocket door in a closed position to close the arm aperture portion in the door when the extension and refraction arrangement is in a storage configuration.
 6. The extension and retraction arrangement of claim 5 further comprising an arm aperture portion in the framework aligned with the arm aperture portion in the door, a flipper door pivotally coupled to the framework, and a means for retaining the flipper door in a closed position to close the arm aperture portion in the framework when the extension and refraction arrangement is in a storage configuration.
 7. The extension and retraction arrangement of claim 6 wherein the door is slidable between the open and closed positions and wherein the means for retaining the pocket door and the flipper door in closed positions comprises an interlocking of the pocket door and the flipper door.
 8. The extension and retraction arrangement of claim 1 further comprising a means for sensing an obstruction to travel of the trolley structure along the elongate support arrangement and wherein the control system automatically terminates travel of the trolley structure and the UP or DOWN sequence in response to the obstruction.
 9. The extension and retraction arrangement of claim 8 wherein the control system permits a user to induce only the UP sequence upon a removal of the obstruction to travel of the trolley structure wherein the DOWN sequence is disabled until the UP sequence achieves the use configuration.
 10. The extension and retraction arrangement of claim 1 wherein the control system automatically terminates the UP or DOWN sequence in response to a power failure and wherein the control system permits a user to induce only the UP sequence upon a return of power wherein the DOWN sequence is disabled until the UP sequence achieves the use configuration.
 11. The extension and retraction arrangement of claim 1 wherein the control system further comprises an installation mode and wherein the extension and retraction arrangement has an installation configuration when in the installation mode with the trolley structure disposed adjacent to the second end of the elongate support arrangement and the door in an open configuration.
 12. The extension and retraction arrangement of claim 11 wherein the control system is adjustable between the installation mode and the operation mode.
 13. The extension and retraction arrangement of claim 12 wherein the control system permits a completion of the UP sequence or the DOWN sequence upon adjustment from the installation mode to the operation mode.
 14. An extension and retraction arrangement with a control system for adjusting a monitor from a retracted configuration to an extended configuration, the extension and retraction arrangement comprising: a trolley structure; a means for retaining a monitor to travel with the trolley structure; an elongate support arrangement with a first end, a second end, and a body portion between the first and second ends; a means for retaining the trolley structure for axial extension and retraction along the body portion of the elongate support arrangement from adjacent to the first end to adjacent to the second end of the elongate support arrangement; a means for propelling the trolley structure to travel along the body portion of the elongate support arrangement; a framework fixed adjacent to the second end of the elongate support arrangement wherein the framework has a centrally disposed aperture wherein the monitor projects through the aperture in the framework when the trolley structure is disposed adjacent to the second end of the elongate support arrangement; a door with an open position and a closed position for at least partially closing the aperture in the framework; a means for propelling the door between an open position and a closed position; a control system for controlling the extension and retraction of the trolley structure and an opening and closing of the door wherein the control system has an operation mode with an UP sequence and a DOWN sequence, wherein the extension and retraction arrangement has a storage configuration with the door in a closed position and the trolley structure and the monitor disposed below the door, and wherein the extension and refraction arrangement has a use configuration with the monitor extended beyond the door and the door in a closed position; and a means for enabling a user to induce the UP sequence and the DOWN sequence; wherein the means for retaining the monitor to travel with the trolley structure comprises a means for pivotally retaining the monitor between an upright configuration and an angled configuration and further comprising a means for sensing whether the monitor is in an upright configuration and wherein the control system automatically prevents extension and retraction of the trolley structure when the monitor is not in an upright configuration.
 15. The extension and retraction arrangement of claim 14 wherein the control system permits a user to induce only the UP sequence upon the monitor being adjusted to the upright configuration wherein the DOWN sequence is disabled until the UP sequence achieves the use configuration.
 16. An extension and retraction arrangement with a control system for adjusting a monitor from a retracted configuration to an extended configuration, the extension and retraction arrangement comprising: a trolley structure; a means for retaining a monitor to travel with the trolley structure; an elongate support arrangement with a first end, a second end, and a body portion between the first and second ends; a means for retaining the trolley structure for axial extension and retraction along the body portion of the elongate support arrangement from adjacent to the first end to adjacent to the second end of the elongate support arrangement; a means for propelling the trolley structure to travel along the body portion of the elongate support arrangement; a framework fixed adjacent to the second end of the elongate support arrangement wherein the framework has a centrally disposed aperture wherein the monitor projects through the aperture in the framework when the trolley structure is disposed adjacent to the second end of the elongate support arrangement; a door with an open position and a closed position for at least partially closing the aperture in the framework; a means for propelling the door between an open position and a closed position; a control system for controlling the extension and retraction of the trolley structure and an opening and closing of the door wherein the control system has an operation mode with an UP sequence and a DOWN sequence, wherein the extension and retraction arrangement has a storage configuration with the door in a closed position and the trolley structure and the monitor disposed below the door, and wherein the extension and refraction arrangement has a use configuration with the monitor extended beyond the door and the door in a closed position; a means for enabling a user to induce the UP sequence and the DOWN sequence; and a means for sensing an obstruction to a movement of the door wherein the control system automatically terminates the UP or DOWN sequence in response to the obstruction.
 17. The extension and retraction arrangement of claim 16 wherein the control system permits a user to induce only the UP sequence upon a removal of the obstruction to the movement of the door wherein the DOWN sequence is disabled until the UP sequence achieves the use configuration. 